Владимир Воеводский (who publishes in English as Vladimir Voevodsky) (web site) is a Russian mathematician working in the Institute for Advanced Study.
He received a Fields medal in 2002 for a proof of the Milnor conjecture. The proof crucially uses A1-homotopy theory and motivic cohomology developed by Voevodsky for this purpose. In further development of this in 2009 Voevodsky announced a proof of the Bloch-Kato conjecture.
After this work in algebraic geometry, cohomology and homotopy theory Voevodsky turned to the foundations of mathematics and is now working on homotopy type theory which he is advertising as a new “univalent foundations” for modern mathematics with its emphasis on homotopy theory and higher category theory.
See also the English Wikipedia article .
An interview is here.